Copper alloys



Patented Oct. 31, 1939 I COPPER ALLOYS William B. Price, Waterbury, Conn., assignor, by mesne assignments, to P. R. Mallory & 00., Inc., Indianapolis, Ind., a corporation of Delaware No Drawing. Application February 23, 1937, Serial No. 127,293

Claims. (Cl. 75-153) This invention or discovery relates to copper alloys; and it comprises an alloy of high strength and resistance to abrasion and excellent electrical conductivity, consisting of copper with a small addition of cobalt and of cadmium and substantially free of other alloying elements; all as more fully hereinafter set forth and as claimed.

In wires for certain electrical transmission purposes, such as trolley lines, it is required that the wire have a high tensile strength coupled with as high a conductivity as possible. Resistance to abrasion is also desirable for such purposes. Pure copper has a higher conductivity than any copper alloy, but its tensile strength is not great and its resistance to abrasion is low. The mechanical properties of copper can be improved,by suitable alloying additions. There are very many additions which can be made to copper to increase the tensile strength and improve its mechanical properties generally. But without exception all additions to copper cut down the conductivity to a greater or less degree; the conductivity of any copper alloy is less than that of pure copper. In making high conductivity copper wire of high tensile strength the result is necessarily a compromise. Silicon in extremely small amounts gives good tensile strength but it also cuts down conductivity; the lessening in conductivity per unit of silicon in the copper if a good conductivity be obtained the tensile strength is low.

I have found that on the whole the best combination of conductivity and tensile strength is given by a rather special alloying addition: co-

balt and cadmium in about equal amounts with the total amounting to about 1 per' cent of the alloyed wire. Such an alloy has ample strength even for long spans of heavy wire, and has a high conductivity; of the order of 44 per cent that of the International Annealed Copper Standard (IACS). Moreover, such alloy has high resistance to abrasion. A trolley wire made of it does not scuff or flow under the pressure of the moving contact element of the engine or car.

As an example of a specific embodiment of the invention, an alloy can be produced, composed This particular alloy has a conductivity of 44 per cent IACS. As hard drawn wire B 8; S numbers) it has a tensile strength of 85,000 pounds per square inch in 0.318 inch gage, and 72,000 pounds per square inch (4 B 8: S numbers) in 0.0635 inch gage. In softcondition (annealed) the tensile strength is 44,000 for a 0.0635 inch gage wire and the elongation is 39 per cent in 2 inches.

In the alloy the proportion of cadmium can be varied within the range 0.05 to 0.95 per cent while achieving similar results, and -the cobalt can be varied within the range 0.05 to 0.95 per cent (by weight). 25 The alloy is particularly useful for electric railway trolley lines and telephone drop wires, but is useful in other connections where its special .properties may be desired.

What I claim is:

1. An alloy of high strength and electrical conductivity consisting of copper substantially 99 per cent, cobalt approximately 0.5 per cent and cadmium approximately 0.5 per cent.

2. An alloy of high strength and electrical conductivity consisting of 0.05 to 0.95 per cent cadmium, 0.05 to 0.95 per cent cobalt, and the balance copper.

,3. An alloy of high strength and electrical conductivity consisting of -more than 0.05 per 40 cent. but less than one per cent each of cadmium and cobalt, and the balance copper, said alloy containing not more than a negligible proportion of other alloying constituents.

4. An alloy consisting of .1 to 1. per cent of cadmium and .1 to 1. per cent of cabalt and the balance copper.

5. An alloy consisting of 0.1 to 0.95 per cent of cadmium and 0.1 to 0.95 per cent of cobalt and the balance copper. e

WILLIAM 13. PRICE. 

